RESUMO
Ursolic acid (UA), which has many biological properties such as anti-cancer, anti-inflammatory and antioxidant, and regulates some pharmacological processes, has been isolated from the flowers, leaves, berries and fruits of many plant species. In this work, UA was purified from the methanol-chloroform crude extract of Nepeta species (N. aristata, N. baytopii, N. italica, N. trachonitica, N. stenantha) using a silica gel column with chloroform or ethyl acetate solvents via bioactivity-guided isolation. The most active sub-fractions were determined under bioactivities using antioxidant and DNA protection activities and enzyme inhibitions. UA was purified from these fractions and its structure was elucidated by NMR spectroscopy techniques. The highest amount of UA was found in N. stenantha (8.53 mg UA/g), while the lowest amount of UA was found in N. trachonitica (1.92 mg UA/g). The bioactivities of UA were evaluated with antioxidant and DNA protection activities, enzyme inhibitions, kinetics and interactions. The inhibition values (IC50) of α-amylase, α-glucosidase, urease, CA, tyrosinase, lipase, AChE, and BChE were determined between 5.08 and 181.96 µM. In contrast, Ki values of enzyme inhibition kinetics were observed between 0.04 and 0.20 mM. In addition, Ki values of these enzymes for enzyme-UA interactions were calculated as 0.38, 0.86, 0.45, 1.01, 0.23, 0.41, 0.01 and 2.24 µM, respectively. It is supported that UA can be widely used as a good antioxidant against oxidative damage, an effective DNA protector against genetic diseases, and a suitable inhibitor for metabolizing enzymes.Communicated by Ramaswamy H. Sarma.
RESUMO
The role of second hand smoke (SHS) exposure on ulcerative colitis is not known. Our aim was to examine the effects of α-lipoic acid (ALA), chronic aerobic (AE) or resistance exercise (RE) on SHS exposed rats with colitis. Sprague-Dawley male rats (150-200 g, n=54) were selected for colitis induction. Among the colitis groups, one group was exposed to SHS (6 d/wk, 4 cigarettes/d) and the other was not. The SHS group was divided into subgroups as follows: sedentary; AE (swimming; 3 d/wk); and RE (climbing with weight; 3 d/wk). After 5 weeks, colitis was induced by intrarectal acetic acid. All groups had subgroups that were given subcutaneously ALA (50 mg/kg per day) or vehicle for 3 days. Following decapitation, colon tissues were sampled to examine malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity, luminol and lucigenin chemiluminenscence, macroscopic scoring and histologic examination. ANOVA and Student's t-test were used for statistical analysis. The increased macroscopic and microscopic scores, MPO, MDA, luminol and lucigenin measurements in colitis and SHS-colitis groups were decreased via ALA (P<.05-.001). AE declined macroscopic and microscopic scores, MDA, lucigenin compared to colitis and SHS-colitis groups (P<.01-.001). RE reduced microscopic score, MPO, MDA, luminol, lucigenin (P<.05-.001) that were increased with colitis. Decreased GSH levels (P<.01) in the SHS-colitis group approached to control levels when given ALA. According to our results SHS and colitis induction increased inflammatory damage. SHS did not worsen it more than colitis. Our results suggest that ALA, AE or RE might be protective for SHS exposed ulcerative colitis conditions.